Apple has a history of silently changing chips/process in small quantities without telling anyone. AFAIR, they changed the soc inside one of the ipad generations a few years ago when going from 32-28nm. There was a while that the current ipad at the time came with one of two different socs, and there was no way to tell, except the newer soc had a longer battery life and the ipad ran cooler.

It would therefore not surprise me if some existing apple products out there are already shipping with a new soc.